The present invention relates to a leakage current preventing means and, more particularly, to a leakage current preventing means for a drier.
In the known drier, the AC source is controlled by a power switch and several rectifiers and the drier itself is not provided with any leakage current protecting means to avoid a possible damage resulting therewith. In order to overcome this imperfection, use of one AC silicon controlled rectifier (TRIAC) in the drier has been attempted for controlling the AC power source, this being a so called AC phase-shift control which controls the voltage supplied to the load (the heater) with the triggering angle of the TRIAC. Since such control merely is designed to control the fire wire of two conductors power-supplied by the AC source, leakage current still is possible because of the uncontrolled ground wire of the two conductors even when the TRIAC is not in conduction. This situation will be more apparent when the drier is dropped into the water, causing a short-circuit phenomenon.
It is therefore attempted by the applicant to devise a leakage current preventing means for a drier to ensure that the drier has no leakage current in any possible case.